1. Field of the Invention
Embodiments of the present invention relate to hydrodynamic oil film bearings used to rotatably support large heavily loaded shafts in various industrial applications.
2. Description of Related Art
There are large shafts (equal to or greater than one meter in diameter) that are subjected to highly loaded rotating applications, where the loads can be applied in variable radial directions. The rotational speeds of such shafts, while not high, also can be variable and can include so called “quiver”, where the shafts experience small oscillatory movements for protracted periods of time without undergoing a complete revolution. In many cases, the shafts also are subjected to bending moments, which can cause misalignment of bearing surfaces.
Large roller bearings are not well suited for use on shafts that experience quiver, as they are unable to maintain the very thin elasto-hydrodynamic film that supports the rollers.
Oil film bearings can provide a practical alternative to roller bearings. Oil film bearings, particularly when used with high viscosity fluids, have shown that they can carry impressive radial loads for indefinite periods of time under a wide range of speed conditions. However, a requirement for the proper functioning of such bearings is that they be able to align themselves with the shafts, particularly in highly loaded applications.